Conventional resistors may be or include materials or devices having designated resistances that provide a resistance to the passage of an electric current. For example, resistors or resistive materials thereof may often be disposed or deposited on a printed circuit to provide resistance to the electric current in a portion of the printed circuit. To change the resistance of a conventional resistor, the dimensions of the resistor or the material utilized in the resistor may be adjusted or modified. In many applications, such as in printed electronics, adjusting the size of a resistor is undesirable. Further, utilizing a number of resistive materials having varying resistances to provide a broad range of resistances is cost prohibitive; and thus, similarly undesirable.
In view of the foregoing, resistors may often be fabricated from resistive polymer-based solutions or inks that may be diluted to tune the resistance thereof. For example, conventional resistors may often be fabricated from dilutable polymer-based solutions incorporating conductive materials, such as multiwalled carbon nanotubes (MWCNTs). While dispersing the conductive materials into organic or polymer-based solutions have demonstrated efficacy, incorporating the conductive materials (e.g., MWCNTs) in an aqueous media or solution that may be utilized in printed electronics or jetting applications (e.g., aerosol jet, ink jet printing, etc.) has proven to be challenging. For example, MWCNTs are not readily dispersed in aqueous media, and functionalizing the MWCNTs to facilitate the dispersion negatively impacts the electrical performance or efficacy of the resulting resistor.
What is needed, then, are improved resistive materials and methods for preparing and utilizing the resistive materials in printed electronics.